Diabetic foot ulcers frequently occur in different locations to previously-healed wounds for patients in diabetic foot remission, according to a secondary analysis of trial data. “Given the significant morbidity, mortality, and resource utilisation associated with foot ulcer recidivism, quality and evidenced-based preventive care is essential,” noted the authors of the investigation, published in the Journal of Foot and Ankle Research.

Conducted by Brian Petersen (Podimetrics Inc, Somerville, USA) and colleagues, the study aimed to cover a neglected area, characterising not only the location of diabetic foot ulcer recurrence, but “the anatomical locations at which diabetic foot ulcers are likely to recur considering multiple wounds during follow-up and the locations of all prior wounds documented in the participant’s history”.

Discussing the limited nature of investigations on this subject, Petersen et al write: “First, these studies considered only the first recurrence and did not report on all locations of previous diabetic foot ulcers. Second, existing data were not stratified granularly by anatomical location.”

In order to examine this topic further, a secondary analysis of existing data from a 129-participant multicentre study was completed. The primary outcome of that investigation, which had an inclusion criteria of patients in diabetic foot remission, was plantar foot ulceration: “each participant was followed for 34 weeks or until withdrawing consent, allowing characterisation of all wounds occurring,” the authors summarised.

Commenting further on how the secondary analysis was carried out, the authors state that they “stratified the anatomical locations of wounds prior to the trial by the following outcome categories during the trial: no recurrence, recurrence to the same anatomical location, recurrence to a different anatomical location on the same foot, and recurrence to the contralateral foot.” During the trial, 92 participants (71.3%) remained in diabetic foot remission.

Results of the secondary analysis showed that a large proportion of wounds (48%) recurred to the contralateral foot. Thirty-five per cent of diabetic foot ulcers recurred to a different anatomical location on the same foot, and 17% recurred at the same location as a previous diabetic foot ulcer.

Explaining the results further, Petersen et al write: “Rates of recurrence remained high during treatment of a wound (0.41 foot ulcers/ulcer-year). Participants had documented wounds to 2.2 distinct anatomical locations on average, and more than 60% of participants had wounds to more than one plantar location by the end of the study.”

The findings, which “suggest that diabetic foot ulcers to patients in diabetic foot remission frequently occur in anatomically-distinct locations”, are said by the authors to have “important implications for preventative care”. Major risk factors for diabetic foot ulcers include peripheral neuropathy and peripheral arterial disease, both of which affect the entirety of both limbs. As a result, Petersen and colleagues assert that “preventative care should be provisioned for both feet and not only on areas of previous ulceration or concern”.

They continue: “Accordingly, patients and caregivers should be educated on the elevated risk to both feet and instructed to thoroughly examine the entirety of both feet daily for discoloration, callus, blisters, fissures, and other pre-ulcerative findings.

“Given our findings of high incidence to the foot without a wound during treatment for a diabetic foot ulcer, providers should also be cognisant of the risk to both limbs and let this insight guide practice. For example, while treating a diabetic foot ulcer, providers should remain attentive to feet without a wound, which may be predisposed to an elevated risk not only chronically—due to neuropathy and arterial disease—but also acutely due to gait deviation and pressure redistribution, secondary to treatment of the wounded foot.”

In their conclusion, Petersen et al affirm that the results of this analysis “better characterise the burden of recurrence” and “may inform improved understanding of the anatomical locations of recurrence”. Furthermore, they state that “these insights may improve practice of preventative care for those in diabetic foot remission, thereby reducing morbidity, mortality, and cost”.